In a recently released video that showed the killing of 21 Christians in Libya, all but one of them Egyptian, the Islamic State issued an ominous warning: “Today we are south of Rome,” one masked militant said. “We will conquer Rome with Allah’s permission.”

To make matters worse, Rita Katz, director of SITE Intelligence Group, pointed out that supporters of the Islamic State have begun using a hashtag to warn of their plan to reach “Rome.”

Exactly what “Rome” means to the Islamic State is unclear — some experts say it may actually be a reference to the United States or Turkey, or even the West in general. But Italy is worried. Libya is just a short boat ride across the Mediterranean. Thousands of refugees already make this journey to Italian shores every year. What’s to stop the Islamic State?

As word of #We_Are_Coming_O_Rome spread across the Italian media, Rome residents took the opportunity to respond to the Islamic State. And they did so in an especially Roman way.